The present invention relates to a nut-locking device.
Many assemblies of nuts and lock-washers are known for preventing the nut from untightening after it has been placed in position and tightened on a bolt.
Document FR-A-2,025,676 in particular describes such an assembly in which a cylindrical collar having internal splines and teeth which axially project is forcefully pressed on the bolt on top of the nut after the latter has been tightened.
The nut has axial apertures adapted to receive the teeth of the collar when it is pressed on the bolt, the latter also having if desired splines corresponding to those of the collar with which they cooperate.
An assembly of this type is relativey effective, but however does not afford complete safety. Indeed, the collar must not move up the bolt away from the nut.
For this purpose, the apertures of the bolt are drilled obliquely and diverge outwardly so as to deform the teeth of the collar which is of a relatively malleable metal and, owing to this malleability, there is a danger that the teeth leave the apertures of the bolt, for example under the action of large vibrations.
In other known devices, described for example document U.S. Pat. No. 3,022,809, a collar is mounted on the bolt with which it cooperates through splines and is then clipped onto the nut.
In all these arrangements, the behavior of the collar depends on the resistance of the latter to deformation, this resistance being however required to permit the initial deformation. Such a compromise is not absolutely reliable and the collar cannot be recovered in the event of disassembly.